Assay (complexometric): 99.0 - 101.0 %

Insoluble matter: ≤ 0.005 %

Free acid (as HNO₃): ≤ 0.3 %

Chloride (Cl): ≤ 0.0005 %

Phosphate (PO₄): ≤ 0.005 %

Sulfate (SO₄): ≤ 0.005 %

Ca (Calcium): ≤ 0.005 %

Cu (Copper): ≤ 0.005 %

K (Potassium): ≤ 0.005 %

Mg (Magnesium): ≤ 0.001 %

Mn (Manganese): ≤ 0.02 %

Na (Sodium): ≤ 0.005 %

Pb (Lead): ≤ 0.001 %

Zn (Zinc): ≤ 0.001 %

Substances not precipitated by ammonia (as sulfate): ≤ 0.1 %

Corresponds to ACS,Reag. Ph Eur